The surface properties and the activities in catalytic wet air oxidation over CeO2–TiO2 catalysts

No-noble metal CeO2–TiO2 catalysts prepared by sol–gel method were developed and examined for catalytic wet air oxidation (CWAO) of acetic acid. The structure of the catalysts was measured by BET, SEM, XRD, XPS and DTA-TG.We investigated the effect of the interactions of Ce and Ti on the structure of CeO2–TiO2 catalysts. The mechanisms of the relationships between the different content of Ti and the activity of CeO2– TiO2 catalysts were discussed. The results showed that the average crystal size of CeO2 decreased and the surface areas increased; the low valence of Ce3+ increase, and the chemisorbed oxygen slightly decreased with the increase of Ti content on the surface of CeO2–TiO2 catalysts. The order of the activity inCWAO of acetic acid followed: Ce/Ti 1/1 > Ce/Ti 3/1 > Ce/Ti 1/3 > Ce/Ti 5/1 > CeO2 > TiO2 > no catalyst. InCWAO of acetic acid, the optimal atomic ratio of Ce and Ti was 1, and the highest COD removal was over 64% at 230 8C, 5 MPa and 180 min reaction time over Ce/ Ti 1/1 catalyst. The excellent activity and stability of CeO2–TiO2 catalysts was observed in our study